114 SEA- WEEDS. 



some fine specimens are ten feet long. It has a 

 thick tough stem, and is of an olive-green, and of 

 leathery texture. In the young plant it is some- 

 times like a thin flat leaf, but when older, its edges 

 are puckered like a frill, and it has a number of 

 raised projections down the middle, being what 

 botanists call bullated or blistered ; while a muci- 

 laginous substance, with which it is covered, comes 

 off on the hand. This sea-weed has a large fibrous 

 root, if, indeed, that can be called a root, which is 

 never intended to penetrate the soil, but only to 

 hold the plant fast to the surface of the rock. It 

 we examine the fibrous root of a land plant (one 

 of the grasses, for example), we find it adapted not 

 only for keeping the plant firm in the ground, but 

 also, by tapering points, and minute orifices at the 

 extremities of its fibres, suited for deriving nutri- 

 ment from the earth. The sea-weeds, however, 

 are little affected by the soils on which they grow, 

 and they seem to require their roots, almost en- 

 tirely, as means of holding them attached to it. 



The Sweet Laminaria (Laminaria saccharina) 

 is called by fishermen the Sea Belt. If washed, 

 and hung up in the sun to dry, it becomes covered 

 with an efflorescence of a white colour, and of a 

 flavour at once of salt and sugar, which is not, 

 however, very agreeable to the palate. This is not 

 the only sea-weed which deposits these crystals ot 

 sweet powder, which are in the form .of needles, and 

 which were by Dr. Stenhouse discovered to be man- 

 nite, the characteristic principle of manna, differ- 

 ing from cane sugar, but resembling that procured 

 from grapes. The quantity of this mannite is very 

 great. Dr. Stenhouse found that one thousand 

 grains of the sea-weed yielded, by means of a 



